Social and non-social autism symptoms and trait domains are genetically dissociable

Abstract

The core diagnostic criteria for autism comprise two symptom domains – social and communication difficulties, and unusually repetitive and restricted behaviour, interests and activities. There is some evidence to suggest that these two domains are dissociable, though this hypothesis has not yet\xa0been tested using molecular genetics. We test this using a genome-wide association study\xa0(N\u2009=\u200951,564) of a non-social trait related to autism, systemising, defined as the drive to analyse and build systems. We demonstrate that systemising is heritable and genetically correlated with autism. In contrast, we do not identify significant genetic correlations between social autistic traits and systemising. Supporting this, polygenic scores for systemising are significantly and\xa0positively associated with restricted and repetitive behaviour but not with social difficulties in autistic individuals. These findings strongly suggest that the two core domains of autism are genetically dissociable, and point at how to fractionate the genetics of autism.Varun Warrier et al. report a genome-wide association study of systemising, a non-social trait associated with autism. They find 3 loci associated with systemising and show that this trait has no significant genetic correlations to social phenotypic measures, demonstrating that the social and non-social aspects of autism are genetically distinct.